The reduction and elimination of, or the recovery of energy from, organic waste from urban activities is a problem that can be approached from several angles, the studies resulting therefrom leading to varying solutions according to the importance attached to the different parameters under consideration.
Formerly, food waste was sold to serve as animal feed. Today, this traditional mode of recycling food waste has given way to a policy of destruction, which is much more expensive. In parallel, there is a growing tendency to increase the intermediate stockage time for waste food, in order to allow more time between collection operations whose cost is also ever increasing.
The solutions imagined to date to combat the risks associated with food waste waiting for collection are refrigeration or partial sterilization using chemical products; both involve the temporary and costly slowing of an uncontrolled biological activity.
In contrast to procedures in use heretofore, the present invention provides for a local and immediate treatment of organic matter to carry out controlled biological processes in a specially designed digestor.
The present invention principally takes into account the mass of kitchen waste to be managed by restaurants serving a large number of meals. The invention is derived from two considerations:
On the one hand, making available to these facilities an anerobic digestor that, while being as compact as possible is able to receive the mass of waste and continually restitute therefrom waste waters, concentrated solid residues and biogas of high-quality (from the point of view of good calorific value and combustibility), responds to a real need.
On the other hand, water purification stations, composting apparatus or other installations of the same type operate conventionally based on the principle that fluxes of organic waste are collected on as large a scale as possible and delivered to a center where the bioconversion process takes place in relatively stable conditions.
Stability is indeed an essential condition for maintaining the biological process for transforming the materials.